<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        var age =100;
        var obj = {
            age: 20,
            say: () =>{
                alert(this.age);
            }
        };
        obj.say();
        //对象不存在作用域,say()方法在全局作用域下
    </script>
</body>
</html>